Form bending machine



May 29, 1934.

E. J. W. RAGSDALE FORM BERDING MACHINE Filed June 20, 1931 2Sheets-Sheet l INVEN TOR.

EARL .IWR/aosmu:

Patented May 29, 1934 UNITED STATES PATENT OFFICE 1,961,109 FORM BENDINGMACHINE ApplicationJuue 20, 1931, Serial No. 545,643

10 Claims.

My invention relates to form bending machines of a type having especialadaptation for the bending of elongated strip stock of narrow crosssection andrelatively light gauge. Its prime objects are the accuratebending of such stock as preformed to desired cross section withoutdistortion of that cross section, a maximum flexibility of adjustment ofthe contours of such bending, a maximum rapidity of such adjustment andits stability, and a maximum output per diem. These objects involve ahigh efficiency at a high speed, yet rapidity of adjustment withfineness. Particularly is the invention adapted for use in bending stripstock sections of metal utilized in the fabrication of structuralframeworks of aerofoils for aircraft. However, there are doubtlessfeatures of the machine having utility in the bending of stock veryconsiderably different in form, grade and weight.

These objects I attain in the main by combining an adjustablework-bending mechanism having a determinate rate of progression withrespect to the work with a relatively adjustable work form-determiningmechanism having a relative rate of progression with respect to thebending mechanism proportional to the rate of progression of the bendingmechanism with respect to the work. The work form-determining mechanismI constitute of a flexible continuous 31} bent contouring elementadjustable by reason of its flexibility transversely of the relativedirection of progression of the said mechanism to vary the work contourthrough its engagement withthe adjustable elements of the work bendingmechanism. A series of contour determining elements adjustabletransversely of this contouring element and relative to each other areutilized to efiect this adjustment through their bearing upon theflexible contouring element. Power is applied to the bending mechanism,and gearing connections between the bending mechanism and the workform-determining mechanism which admits freely of the relative movementsof adjustment assures the proportional movements of progression. Thebending mechanism is of a three roll type the rolls of which havefeatures especially adapting them tothe work. The extreme rolls are ofrelatively small diameter. Two intermediate rolls are used movable inunison and having mating crosssections complemental to and engaging theopposite contours of the cross section of the strip to be rolled. Theextreme rolls are set close in to the intermediate rolls. Theintermediate rolls constitute the adjustable 55 portions of the bendingmechanism.

In the accompanying drawings- Figure 1 is a front elevation of themachine. Figure 2 is a rear elevation.

Figure 3 is an end view from the right hand side as viewed in Fig. l.

Figure 4 isa transverse cross section on the axes of the intermediaterolls on line 4-4 of Fig. 1.

Figure 5 is an enlarged longitudinal section through the rolls of thebending mechanism approximately in the plane 5-5 of Fig. 3.

Figure 6 is an enlarged perspective of oneof the contour determiningelements of the work form-determining mechanism.

Figure 7 is a side elevation of an airplane wing rib the chord elementsof which at least may be formedon the machine of my invention.

In the embodiment disclosed (which by the way is only one of manyembodiments which my invention may be given) the main frame of themachine is composed of a pair of uprights 10 interconnected in theirupper'. portions by a plate 11 which constitutes the mounting means forsubstantially allelements of the machine.

The bending mechanism designated 12 in gen- 1 eral is arrangedsubstantially vertically of the middle portion of the plate 11. Itcomprises-the extreme rolls 13 of relatively small diameter which havetheir axes located in the transversely extending plane and are supportedfrom the front of the plate 11 by means of bearing blocks 14 at an angleto each other and removably and adjustably secured to the plate 11 bybolts 15. The intermediate rolls 16 and 17 ofrelatively large diameterare arrangedon opposite sides of the plane of axes of rolls 13 and areof mating cross sections, as clearly appears in Figs. 1 and 3 to5,'complemental each to a side 'of, the angle or channel shaped crosssection of the work 18. This work is illustrated as a piece of channelsection strip stock 18 and the cross sections of rolls 16 and 1'! 'arefixed accordingly. Rolls 16 and 17 are carried respectively on stubshafts 19 and 20 of stepped longitudinal cross section as appears inFig. 4, each removably secured through removable nuts 21 in a verticallyadjustable head stock 22 adjustably borne from plate ll by guides 23.13y removing and replacing shafts 19 and 20, intermediate rolls 16 and17 may be removed and replaced and changed at will to accommodate themachine to various cross sections of stock. Roll 16 is fixedlypositioned on the head stock 22 while roll 1'7 is relatively adjustablethrough its journaling in a slide 24 vertically adjustable in guides 25on the head stock by means of a hand screw 26.

This aifords proper roll clearance and adjustment to gauge.

The work form-determining mechanism design'ated generally 27 is arrangedat the top of the frame 10-11 in such a manner as to be afforded arelative movement or progression as respects .the bending mechanism 12transversely of the machine and the adjustable head stock 22. Itcomprises an elongated transversely extending base plate 28 having fixedthereto in spaced relation from its lower edge a rack 29 supported frombrackets 30. Jibs 31 extending laterally of the rack as shown,particularly in Figs. 2 and 4, are borne in spaced ways 32 on the rearof the plate 11, affording means for relative progressive movement ofthe form mechanism. The jibs are comprised of underlying rollers 33 andoverlying guides 34 mounted in part on the back of plate 11 and in partby brackets 35; Adjustable steps 36 at opposite ends of the mountingplate 28 are adapted to engage by their juxtaposed ends 37 the sides ofthe head stock 22 (see Fig. 1) and limit the extent of relative movementof work form-determining mechanism 27 and work bending mechanism 12. O

Extending in the general direction of the rack 29 and hence in thegeneral direction of the relative progressive movement and mounted onthe front face of mounting plate 28 (see Fig. 1) is the flexiblecontouring element or strip 38. By reason of its flexibility it isadjustable transversely of the general direction of such progressivemovement. A series of, contour determining elements 39 are arranged tobear transversely uponthe strip 38 and determine the form of itscontour. These form determining elements 39 are constructed, as shown inFig. 6, to receive endwise the strip 38 in the shouldered recess 40, toretain it therein against transverse dislodgment by reason of theshoulders 41 and to expose unobstructively throughout its length theunder surface of the strip 38 through the open-mouths 42 of the recess.Members 40 are adjustably secured to mounting plate 38 by bolts 43 intransversely extending slots 44. Relative adjustment of the formdetermining members 39 transversely flexes the strip 38 to any contourdesired as clearly appears in Fig. 1.

The under side of the strip 38 as exposed through the mouths 42 ofrecesses 40 receives the follower 45 in the form of a roller carried atthe top of the head stock 22 of the bending mechanism 12 (see Fig. 4particularly). The arrangement of this roller is such that itconstitutes the sole and direct adjusting contact between contouredstrip 38 of the work form-determining mechanism and the adjustable headstock 22 bearing the intermediate rolls 16 and 17. This roller is homeup against the under side of form 38 constantly by a potential energydevice in the form of a spring 46 housed within the head stock (seeFigs. 1 and 2) and exerting its pressure between a fixed abutment 47projected within the hollow of the head stock 22 from the plate 11 andan adjustable abutment 48 in the form of a screw threaded verticallyinto the top of the head stock 22. Thereby the intermediate rollers 16and 1'7 and the bending mechanism 12 are caused to be automaticallyadjusted precisely in accordance with the contour of the strip 38.

The work bending mechanism 12 and the work form-determining mechanism2'7 are geared together for maintenance of their proportional promeansof meshing roll gears 49 on the shafts 19 and 20 of the inand 1'7) andby means of reducing gear and pinion 52-53, which latter meshes directlywith the rack 29. The pivotal axis or shaft 51 of the oscillatablelinkage 50 and the shaft 54 of the gears 52-53 are borne from the rearof the plate 11, (Fig. 2), by means of a bracket 55 (see Fig. 3).

Power is applied through the shaft 51 in the instance illustrated bymeans of a hand crank 56.

The operation of the machine is almost if not quite fully apparent fromthe drawings and the description up to this point. Suffice it to say butthat once the rolls 16 and 17 have been chosen with respect to thesection of the work 18 to be rolled, mounted in place and given theproper setting with respect to -each other by means of adjusting screw26, and once the flexible form strip 38 has been adjusted to contour bythe transverse setting of its form determining members 39, and the stops36have been set to determine the extremes of movement, one has but toinsert strip after strip of the work 18 between the rolls of the bendingmechanism and on each reciprocation of the forming mechanism 2'7 9.piece of work is completed, accurately bent to the contour of the formoutlined by the member 38 and having its section accurately preserved bythe complementally sectioned intermediate rolls 16 and 1'7. The closeproximity of the extreme rolls 13 to the intermediate rolls 16 and 17insures bending on smallradii and bending in conjunction with thecomplementally sectioned rolls 16-17 aids in the maintenance of crosssection during bending.

The machine as shown in this embodiment is a reciprocatory machinerequiring reversals of relative progression of proportional movement onthe completion of each piece of work as a condition precedent tostarting a succeeding piece. It is conceivable that other embodiments ofthe machine might be given a continuous motion of progression in onedirection. Many other modiflcations might be made in'other embodimentswithout departing from the generic spirit of the invention. Accordingly,the circumstantial terminology of the claims should be vested with thegeneric spirit of the invention in the process 0t their interpretation.

What I claim as new and useful and desire to protect by Letters Patentis:--

1. A progressive work bending machine comprising adjustable work bendingmechanism having means for causing relative progressive movement betweenthe work and itself, a relatively progressive work form-determiningmechanism for automatically adjusting the said bending mechanism, andmeans gearing said mechanisms together for equal progressions ofmovement of the bending mechanism with respect to the work and the workform-determining mechanism with respect to the bending mechanism.

- 2. A progressive work bending machine comprising adjustable workbending mechanism having means for causing relative progressive movementbetween the work and itself, a relatively progressive workform-determining mechanism for automatically adjusting the said bendingmechanism, and gearing connections between said two mechanisms embodyingbodily fixed gears driving one mechanism and connected to relativelybodily movable gears connected with the other mechanism.

3. A progressive work bending machine comprising work bending mechanismhaving means for causing relative progressive movement between the workand itself, a relatively progressive work form-determining mechanism forautomatically adjusting the said bending mechanism relative thereto, andmeans for causing said form mechanism to progress at a rate proportionalto the rate of progression of the work with respect to the bendingmechanism, together with a potential energy device continuously urgingthe relatively adjustable elements of said two mechanisms towards eachother, and a power drive for said bending mechanism having a gearingconnection with the work form-determining mechanism admitting therelative adjustments of said mechanisms while maintaining theirproportional progressive movements.

4. A progressive work bending machine comprising adjustable work bendingmechanism having means for causing relative progressive move mentbetween the work and itself, a relatively progressive Workform-determining mechanism for automatically adjusting the said bendingmechanism, and means for causing said form-determining mechanism toprogress at a rate proportional to the rate of progression of the workwith respect to the bending mechanism;

5. A progressive work bending machine comprising adjustable work bendingmechanism hav ing means for causing relative progressive movementbetween the work and itself, a relatively progressive workform-determining mechanism for automatically adjusting the said bendingmechanism, means for causing said form-determining mechanism to progressat a rate proportional to the rate of progression of the work withrespect to the bending mechanism, and means for adjusting theform-determining mechanism to vary the form of bending.

6. A progressive work bending machine comprising adjustable work bendingmechanism having means for causing relative progressive movement betweenthe work and itself, a relatively progressive work form-determiningmechanism for automatically adjusting the said bending mechanism, andmeans for causing said work form-determining mechanism to progress at a.

rate proportional to the rate of progression of the work with respect,to the bending mechanism, said form-determining mechanism comprisingaseries of contour determining elements adjustable transversely of therelative direction of progression, of the form-determining mechanism andrelatively to each other to vary the form of the bending.

'7. A progressive work bending machine comprising adjustable workbending mechanism having means for causing relative progressivemovementbetween the work and itself, a relatively progressive workform-determining mechanism for automatically adjusting the said bendingmechanism, and means for causing said formdetermining mechanism toprogress at a rate proportional to the rate of progression of the workwith respect to the bending mechanism, said form-determining mechanismcomprising a flexible contouring element extending in the generaldirection of relative progression of the form-determining mechanism, andadjustable transversely of said direction to vary the form of thebending.

8. A progressive work bending machine comprising adjustable work bendingmechanism having means for causing relative progressive movement betweenthe work and itself, a relatively progressive work form-determiningmechanism for automatically adjusting said bending mechanism, and meansfor causing said formdetermining mechanism to progress at a rateproportional to the rate of progression of the work with respect to thebending mechanism, said form-determining mechanism comprising acontinuous flexible contouring element extending 100 generally in thedirection of relative progression of the form-determining mechanism andengaging with the bending mechanism, together with a plurality ofcontour-determining elements along the length of the flexible contouringelements and adjustable transversely thereof to vary its contour.

9. A' progressive work bending machine comprising adjustable workbending mechanism having means for causing relative progressive'movementbetween the work and itself, "a relatively progressive workform-determining mechanism for automatically adjusting the said bendingmechanism, means for causing said form-determining mechanism to progressat a rate proportional to the rate of progression of the work withrespect to the bending mechanism, which bending mechanism. comprisesthree rolls, one of which is adjustable relative to the other two, andmeans controlled by said form-determining 120 mechanism forautomatically adjusting said roll.

10. A progressive work bending machine comprising adjustable workbending mechanism having means for causing relative progressive movementbetween the work and itself, a relatively 135 progressive workform-determining mechanism for automatically adjusting the said bendingmechanism, and means for causing said form-determining mechanism toprogress at a rate proportional to the rate of progression of the work130 with respect to the bending mechanism, together adjustable stopslimiting the extent of relative progression in each direction ofmovement of said mechanism.

